Diamond Color Overview
Color is the second most significant grading aspect of buying or selling diamonds. Diamonds are graded based on their overall body color, on a scale developed by the GIA. This scale runs from "D" to "Z". Note in the charts below how the difference between any two colors can be very subtle.
Below is a Diamond Color Master Grading Set showing the full color range, from a D all the way to a Z. You would never need a color grading set that goes this far, but this is an striking example of how extreme the range can be.
To achieve the highest degree of accuracy, diamonds must be color graded loose and with the proper equipment. The stones should be upside down to provide the best viewing of the crystal color, and a proper "North Light" source should be employed. Any diamond grade offered while a stone is still in its mounting should be noted as provisional, based on the limitations of grading a mounted diamond.
Colors D, E, F
The D-E-F colors are known as the colorless grades. Grade "D" is reserved for larger diamonds whose colors can be more accurately graded due to their size. Diamonds less than .50 carats usually receive a top grade of "F" due to the greater difficulty of precisely grading a small diamond.
Colors G, H, I
These are known as the "face white" or "face up colorless" grades because they appear colorless when viewed through the "face up" position or through the table, but show a slight tint of color when turned upside down for proper grading. This is due to the brilliance of the stone masking this very slight tint when viewed through the table.
Colors J, K, L
This grading range offers some nice diamonds if they are proportioned properly. A well cut diamond of the K-L color range will still appear mostly colorless and can save you a good deal of money over a color grade of a higher range. Again, the cut is the key to keeping the stones of slight tint beautiful.
Colors M to Z
The lower colors "M" through "Z" have an increasing amount of yellow tint, ranging through the off colors and ending at the end of the scale, beyond which diamonds are considered to have a fancy yellow color. Be wary of jewelers offering fancy yellow colored diamonds, however. Sometimes they grade off color yellows as fancies without a proper gemological evaluation by a recognized gemological laboratory. The term fancy beside any diamond color imparts a higher value and higher price to the stone. Do not accept the term fancy for any diamond you purchase unless it is accompanied by an origin of color report and a diamond grading report from a recognized gemological lab that identifies the stone as being of natural color origin and truly fancy in color.
Diamonds exist in almost every color of the rainbow, from the very rare red to the sometimes radioactive greens. The natural fancy colors are quite expensive in most colors, with the exception being the brown colors. These can range from fancy champagne down to an unattractive brownish color. The lower quality brown diamonds are often used in cheaper promotional quality jewelry items, such as those sold by Wal-Mart, Sears and discount stores. These diamonds are very cheap and are why these stores can sell 1.00 ct diamond tennis bracelets for $299.00 or less. (To make these diamonds more appealing, a new term TLB, or Top Light Brown, is used). And while the browns can look beautiful in the fancy colors, most promotional quality jewelry uses off color “brownies,” which are much less attractive.
Diamond Color Grade Summary
Regardless of what anyone tells you, it is extremely difficult to color grade diamonds by eyesight alone. The most accurate method employs a master color grading set in a controlled lighting environment...and most important, a gemologist with extensive experience in diamond color grading. People who handle diamonds daily, such as diamond dealers, can often make a close judgment call on a diamond's color simply by eyesight. However, since there is such a wide price range based on minute color grade variations, you should never take someone's word for a diamond grade unless they have been tested and qualified by a proper gemological institute. Make sure that the diamond you buy has been graded by a proper gemologist using the proper tools. Otherwise that slight difference, difficult to see with the unaided eye, could cost you a lot of money.